The present invention relates to a method for processing a volume model, in particular an anatomical model, with at least one object intended to be added to or subtracted from said model. The volume model includes a set of points arranged according to a spatial grid in a first reference system, each of said points being assigned an intensity value. The object includes a plurality of points positioned in a second reference system that is distinct from the first reference system.
The method includes the calculation, for each point of the object, of an image point in the first reference system using a transfer function for transferring from the second reference system to the first reference system.
The invention also relates to a computer program product comprising of software instructions that, when run by a computer, proceed to implement such a processing method.
The invention also relates to an electronic processing system for processing a volume model with at least one object intended to be added to or subtracted from said model.
The invention in particular relates to the field of medical imaging, such as cross sectional medical imaging towards surgical ends. The volume model is an anatomical model that is in conformity with the DICOM format (abbreviated from Digital Imaging Communication Object Model), and thus the first reference system is then in conformity with the DICOM format. The object intended to be added to or subtracted from the anatomical model is initially recorded in a separate format distinct from the DICOM format, and the object is an implant intended to be inserted into the anatomical model. Alternatively, the object is a part of the anatomical model intended to be removed.
In addition to the anatomical data, the first model may include functional data, such as functional data related to magnetoencephalography, also referred to as MEG functional data. The first reference system is then modified to conform to the Talairach reference system.
One method of the abovementioned type is already known. The volume model is an anatomical model, such as a model reconstructed based on images obtained according to an imaging technique using magnetic resonance imaging (MRI) and formed of a plurality of parallel planes, two adjacent parallel planes being spaced apart by a given distance corresponding to a sampling interval, along a direction perpendicular to the parallel planes. Each plane of the anatomical model corresponds to a cross sectional image. The volume model is defined in a first reference system, the set of points forming this model being positioned in this first reference system.
In the event of addition to or subtraction from this model of an object defined in a second reference system that is distinct from the first reference system, a transfer function is applied to each of the points forming the object in order to effect the change of reference system from the second reference system to the first reference system.
However, with such a method, the rendering of the volume model is not optimal following the addition or subtraction of the object, the object being added or subtracted not always being clearly visible.